1. Field of the Invention
This invention relates generally to a method for chemical addition utilizing adaptive process control optimization. More particularly the invention relates to a method for chemical addition utilizing process control optimization having a combination of expert system(s), neural network(s) and genetic algorithm(s).
2. Background of the Invention
Process control systems are used in a variety of applications to sense process conditions and adjust process operating parameters in an attempt to optimize performance for given sets of goals. Many current conventional process control systems use static representations of the process to be controlled and do not provide for changes in the process control model being used in real time.
In conventional adaptive control theory, a suitable controller structure is chosen and the parameters of the controller are adjusted using static rules so that the output of the process follows the output of the reference of the model asymptotically. Static rules do not permit a process control system to automatically and optimally adapt to changing process conditions.
One significant deficiency of prior art process control systems, whether or not adaptive, is their lack of an intuitive user interface, either for initially configuring a system or for interacting with the system in real-time.
Another significant deficiency of prior art process control systems, whether or not adaptive, is the inability of the process control system to automatically perform control actions and, in so doing, provide a global goal-seeking mechanism that ties the process control system together into a powerful unified system to achieve virtually global level optimization congruent with management objectives and goals. This deficiency results from prior art having limited levels of control point, component, and/or system modeling or control hierarchies. Accordingly, many prior art process control systems, whether or not adaptive, cannot provide concurrent multi-level optimization ranging from specific, component-oriented, narrowly focused levels to the broadest, global level.
Traditional process control systems are built up of discrete components (e.g., physical or real-world devices including instrumentation, meters, sensors, controllers, analyzers, actuators, switches, relays, etc.) that work independently and lack low-level optimization. Some process control systems optimize on a system level without regard to optimization at each component level, while still other systems optimize only at the component level. As no global goal-seeking mechanism ties the parts together into a powerful unified system to achieve management objectives and goals, the overall process fails to achieve virtually global level optimization and integration of low-level or component level optimization with the higher level or system level optimization.
The present invention provides a method of chemical addition using process control automation. The present method for adaptively controlling the rate of addition of a chemical to a process comprising: conducting a process which is controlled by a distributed control system; utilizing an adaptive process control optimization system in a host relationship to the distributed control system wherein the process control optimization system provides (i) a plurality of goal seeking intelligent software objects (hereinafter xe2x80x9cISOsxe2x80x9d) further comprising sensor software objects providing current data, historical data, and statistical data; (ii) expert system software objects providing at least one associated rules knowledge base; (iii) adaptive models software objects providing at least one modeling methodology; (iv) predictor software objects providing at least one predictor selection criteria; (v) optimizer software objects providing at least one goal and at least one process constraint; (vi) communications translator software objects providing one or more data communications protocols for a given sampling delta, comprising the concurrent steps of: determining, within the optimizer software objects, output data values which achieve the goals without violating the process constraints; examining, within the expert system software objects, the predictive models that achieve the goals without violating the process constraints; determining, within the expert system software objects, at least one adaptive intervention; providing the at least one adaptive intervention as an input to a distributed control system; and utilizing the at least one adaptive intervention input to the distributed control system for controlling the process.
As more fully described herein below, the present invention provides a method of chemical addition utilizing process control optimization system that achieves, in substantial measure, these above stated objectives by including intelligent software objects (hereinafter referred to as an ISO or ISO""s); an adaptive process control optimization system comprising ISO""s; a method of initializing the adaptive process control optimization system; and a method of human interaction with the adaptive process control optimization system